1. Field of the Invention
The invention relates to techniques for performing wellbore operations. More particularly, the invention relates to techniques for determining downhole parameters of, for example, downhole fluids and/or subterranean formations.
2. Background of the Related Art
Oil rigs are positioned at wellsites for performing a variety of oilfield operations, such as drilling a wellbore, performing downhole testing and producing located hydrocarbons. Downhole drilling tools are advanced into the earth from a surface rig to form a wellbore. Downhole fluids are often pumped into the wellbore as the drilling tool advances into the earth. The downhole fluids may be used, for example, to remove cuttings, to cool a drill bit at the end of the drilling tool and/or to provide a protective lining along a wall of the wellbore. During or after drilling, casing is typically cemented into place to line at least a portion of the wellbore. Once the wellbore is formed, production tools may be positioned about the wellbore to draw fluids to the surface.
During drilling, measurements may be taken to determine wellsite conditions. In some cases, the drilling tool may be removed so that a wireline testing tool may be lowered into the wellbore to take additional measurements and/or to sample downhole fluids. Downhole measurements taken by drilling, testing, production and/or other wellsite tools may be used to determine downhole conditions and/or to assist in locating subsurface reservoirs containing valuable hydrocarbons. Such wellsite tools may be used to measure and/or determine downhole parameters, such as temperature, pressure, viscosity, resistivity, etc. Such measurements may be useful in directing the oilfield operations and/or for analyzing downhole conditions.
Some measurement techniques have been developed for positioning sensor pads in a wellbore to take downhole measurements as described, for example, in Patent/Application Nos. US20080288171, and EP2182391. Some downhole measurements may be used to measure parameters of downhole fluids as described, for example, in U.S. Pat. No. 7,066,282, U.S. Pat. No. 7,394,258, U.S. Pat. No. 7,397,250, U.S. Pat. No. 6,801,039, and EP2182391.
Despite the development of techniques for measuring downhole parameters, there remains a need to provide advanced techniques for determining parameters of downhole fluids and/or subterranean formations. It is desirable that such techniques take into consideration the wellbore conditions that may affect downhole measurements. The invention is directed at achieving these techniques.